Isadora according to the Bootstrap Documentation the way to make the form "inline" is this link
Your code had a few basic questions like the <label>
tag without being closed and other html organization structure issues.
I made this template by blending your code and the Bootstrap documentation, I think it can serve you the way you want it.
In the first example * is within the same
Col-
of
<input>
already in the second example * is separated in a
Col-
and
<input>
in another
Col-
(but everything is inline type)
<link rel="stylesheet" type="text/css" media="screen" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" />
<form class="form-inline">
<div class="form-group">
<div class="col-md-3 col-sm-3 col-xs-3">
<label for="" class="control-label">*</label>
<input type="number" id="" name="protocolos[]" class="form-control" style="width:65px;display:inline"/>
</div>
</div>
<div class="form-group">
<label for="" class="control-label col-md-1 col-sm-1 col-xs-1">*</label>
<div class="col-md-3 col-sm-3 col-xs-3">
<input type="text" id="" name="siglas[]" class="form-control" value="'.$sigla.'" style="width:65px;display:inline"/>
</div>
</div>
</form>
Any doubt is just to speak